Tractor



FIG. 1 is a front perspective view of a tractor showing our new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a left side view thereof; and,

FIG. 8 is a right side view thereof.

The broken lines shown in the drawings are included for the purpose of illustrating environment and form no part of the claimed design. 

CLAIM The ornamental design for a tractor, as shown and described. 